http://modmyi.com/forums/3g-s-downgrading/685331-howto-setup-local-3gs-restore-verification-server-ecid-shsh.html
Check out the above link for more indepth directions on downgrading if you have your info on Cydia.
When you go into Cydia, if it doesn't say at the top of the screen "This device has a 3.0 ECID SHSH on file." (or 3.0.1) at the top of the web page above "Welcome to Cydia" you will only be able to back up your 3.1 ECID SHSH
Which means you can't downgrade to 3.0
see the thing is i backed the ecid when i did have cydia but i dont anymore becuase i did a update using the official firmware because i didnt need the unlock i just wanted a jailbreak... will it still be stored on cydia if i did it before?
well i knew i screwed up and lost to jailbreak my iphone cos of the update. so i did a crafty one. i opened up my sim slot and got a screwdriverand messed it up inside so when i now put the sim card in it doesnt detect the simcard muhahahah. took it to the apple shop and they gave me a replacement immediatly and i now have a 3.0.1 software
now ive jailbroken that and immediatly sent my ecid off to cydia but my question is how long does it take to do it? mine was done 6 hours ago and it still says "This device has a pending TSS request"
and once it has been stored on the cydia am i safe to jailbreak to 3.1 then?
thanks for replies earlier
Pretty crafty..
You can jailbreak to 3.1, because from what I gather, 3.0 and 3.0.1 ECID's are no longer being signed by Apple since 3.1 dropped.. so I don't believe your 3.0.1 info is going to get stored to Cydia.
The best you're going to get is, JB and update to 3.1, then do the Cydia thing which will house your info for 3.1 on file for future endeavors..